Counterbalanced hinge



2 Sheets-Sheet 1 INVENToR. /aafa/'a/J/zzef H. J. DAENZER COUNTERBALANCED HINGE oct. zo, 19.64

Filed Sept. 15. 1961 Oct. '20, 1964 Filed Sept, 15, 1961 H. J. DAENZER COUNTERBALANCED HINGE 2 Sheets-Sheet 2 IN1/Emol@ M11/ard faefrzw' HTTO/VEY Y of this type.

United rStates Patent O CUNTERBALANCED IMGE Howard 3. Daenzer, Detroit, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of VDelaware Filed. Sept. 1,5, 1961, Ser. No. 138,518 Claims. (Cl. 16--128.1)

`This invention relates to hinges, and particularly arrangements for counterbalancing the weight of a closure hinged for movement .against gravity and wherein `the hinge is of the multi-link type.

The invention, although not limited thereto, has particular advantage in counterbalancing hinged movements of a lid-like closure whichl has substantial overhang at its hinged side, requiring bodily as well as pivotal movement at its hinged side to avoid interference, with adjacent structure during operation. Also, the invention is especially advantageous in those installations where the hinging structure must be both concealed from view when the lid is in closed position and located forwardly of such overhang, and where good stability of the lid in all operative positions is essential. f

Such requirements apply with increasing importance to proper hinging ofV automotive vehicle front-engine hoods which open upwardly at their forward ends, because of the trend toward larger and heavier hoods with narrower exposed cowl surfaces between the hood and windshield. Narrowing they exposed surface of the cowl requires longer overhang of the hood'at this' end because the hinging structure must still be located for practical purposes on the dash panel, which, in turn, must belocated well `forwardly ofthe windshield to accommodate the multitudinous accessories and the heating and air conditioning passages, etc., which are located under the cowl. The conventional Vmulti-link type hinge has had to be physically enlarged and strengthened over the'years to cope'with the high spring forces required to satisfactorily counterbalance the increasingly heavy hood panels being used. The larger springs, however, consume an appreciable amount of space under the hood which is required for the engine and its increasing number and size of auxiliary units, as well as yfor such items as power steering, storage battery, brake booster, air conditioner, etc.

I have conceived 0f a novel arrangement of Vtorsion spring for use with such multi-link hinges which greatly reduces the space problem inherent in all known prior hinges In accordance with my invention, the torsion spring is preferably arranged to closely underlie and move with the hood adjacent its hinged edge or side. It exv tends transversely, of the directionY of hinging movement and has a crank portion operable of an idler link pivotally connected to one of the swinging links of the hinge mechanism. In the case of an automotive vehicle hood employing a four-link type hinge, this pivotal connection of the idler link is preferably made to the forwardmost of the two swinging links of the hingeso as to be clear of any interference with the hood to cowl overhang. The torque reaction of the torsion spring is taken by the hood, as by suitable anchorage provided in the movable bracket for vthe companion'hinge on the opposite side ofthehood. Y To minimize the torsional stress imposed onthe spring during operation between closedand full open positions,

the effective length of the spring crank arm is made subtending in a direction normal to the plane of hinging movearenas?? ment and having a crank portion connected by an idler link to one of the swinging links of the hinge, the torsion spring having its reaction taken by the movably hinged member.V

The means by which this and other objects and advantages of the invention are attained will be clearly understood from the following description of one physical embodiment thereof selected for illustration, wherein: y FIGURE l is a perspective View `of an automotive vehicle having its engine hood hinged and counterbalanced in accordance with the invention. a

FIGURE 2 is an enlarged fragmentary side view of the vehicle shown in FIGURE 1, with portions broken away and in section to better illustrate the detail parts of the counterbalanced'hinge, which in this View is shown in the hood closed position. Y i

FIGURE 3 is a View similar to FIGURE 2 except with the parts shown in the hood open position;

FIGURE 4 is a top plan View with portions broken away and in section showing the parts in the hood closed` 6, access may be had to the engine and other power equipment located thereunder. As is conventional, two hinges are provided, one located at either sideof the hood, and these hinges' are designated generally by the numerals 7 and 8.

Since the two hinges are of corresponding construction,

i only the left-hand hinge 8 need be described in detail hood rear edge 5. Below this movable bracket is' a second link in the form of a fixed bracket 11 secured as` by bolts 12 to the side of the opening 2Y and to the vertical Wall 13 which constitutes the vehicle dashwpanel.

At its upper end, this dash panel is turned rearwardly to form the cowl 14, and the extreme rearward portion 15 of this cowl is externally exposed `to form the outer configuration of the vehicle bodyfbetween the vrear end 5 of the hood and the windshield 3. Since it is necessary to enclose various accessories within the space defined rearwardly of the dash 13 and below the cowl 14, and to employ portions of this structure as heating and air conditioning passages for the vehicle, it is essential i that the lhood hinge structure, particularly the iixed bracket 11, be-located forwardly of the dash 13.( Also, since it is desired for optimum external appearance of the vehicle that the exposed portion 15 of the cowl be relatively narrow, it results that the hood 4i has a substantial overhang portion 16 bridgingthe spaceY between-the exposed cowl portion 15 and the dash 13. l A i Returning. again to the construction of the hinge 8, inter-connecting the movable bracket 9 and the fixed bracket 11 are a forward link 1'7 and a rearward link .18, each having pivotal connections at their opposite ends with the respective brackets 9 and 11. These pivotal connections, shown in the form of rivets 19, accommodate swinging movements of the main links 17 and 18 between the openv hood position shown in FIGURE 3 and the closed position shown in FIGURES 2 and 4. It will be appreciated that during such movement between naa-.atea oct. zo, 1964 these two positions of the hood the two main links 17 and 13 eiect both a pivotal and bodily movement of the rear edge of the hood so as to avoid interference with 'the adjacent cowl structure 14 and 1S. To counterbalance .the weight of the hood during such opening and closing movements thereof I employ a torsionally elastic member or spring, shown in the form of a wire rod 2li which extends normal to the plane of the swinging links and whichis arranged to closely underlie and move with the hood adjacent its hinged end. A generally J-shaped notch 21 is for-med in the movable bracket 9, providing means for insertion and journaling at 22 of its adjacent end of the rod 20. Outboard of the bracket 9, the rod is formed with a crank portion 23 which pivotally connects an Vidler link 24. The pivotal connection 25 of the rod to this idler link may be simply formed, as shown, by extending the crank portion 23 through 4the rearwardly extending end of this link 24. At its forward end the idler link has a pivotal connection with the main forward link 17 of the hinge, this pivotal connection being shown in the form of la rivet 26. It will be noted that the effective length of the crank .portion 23 is substantially greater than the distance between the pivotal connections 19 and 26 on the forward link 17. As its reaction means, the opposite end of the torsion rod 2) terminates in a rearwardly bent 'portion which is retained .against rotation by the movable bracket 27 of the opposite hin-ge 7. Although such construct-ion and retention or" that end of the torsion rod 20 for the hinge 8 is not clearly shown in the drawings, it should be understood that the right-hand |hin ge 7 is similarly counterbalanced by a like torsion rod 28 having its reaction endl 29 correspondingly retained by the movable bracket 9 of hinge 8 as clearlyl shown in FIG- URES 2, 3, 4. YIt will also be appreciated that the coun terbalancing torsion'rod 28 for the rightdhand hinge 7 has a crank portion similar to that shown at 23 for rod 28, vand that such crank portion is similarly connected by an idler link 31 to the main forward link 30 (FIGURE l).

Before installation, each or the'torsion rods is prestressed torsionally such that its cran-k portion (23 of rod 20) and its rearwardly bent portion (-29 of rod 28) tend to rotate in counter-clockwise and clockwise directions, respectively, as viewedin FIGURES 2 and 3. As the result, both ends of each torsion rod apply torque tending to open the hood. That such isthe case at the crank portion end will be seen from the `fact that the tendency of each crank portion to rotate counter-clockwise imposes a tensile force on its adjacent idler link (24 o r 31) and a compressive force on its adjacent movablehinge bracket (9 or 27). Considering, for example, the left-hand hinge 8 as viewed in FIG- URES 2 and 3, these tensile and compressive zforces act at pivotal connections 25 and 22 of a'quadric-crank linkage, whose other two pivotal connections are at 26 and 19. The resulting torce couple transmitted to the pivotal conf nections `26 and 19 operates' in a counter-clockwise direction, tending to swing both the hood 4 and the forward link I17 in the hood-.opening direction (from their positions shown in FIGURE 2, to those shown Iin FIGURE 3).

That the tendency of the rearwardly bent portion at the opposite end of each torsion rod to rotate clockwise (as the result of the torsion rod pre-stress) serves also to bias the hood in the opening direction will be obvious on inspection, for example, of the relation of such portion 29 of rod 28 in FIGURES 2 and 3l The tendency thereof to rotate clockwise is transmitted directly to movable bracketV 9, tending to rotate it and the hood therewith in the clockwise direction about the pivotal connection 19 on rear link 13. In operation, during raising of the hoodfrom its position shown in FIGURE 2 to its open position shown in FIG- URE 3, the main links 17 and `18 of the hinge 8 -and the corresponding links 30 and 32 of the hinge 7 swing upwardly about their'pivotal connections on their fixed brackets in a counter-clockwise direction as viewed in FIGURES 2, 3 and 4. Since the forward links 17 and 30 are longer than the rearward links 18 and 32, the hood undergoes a combined bodily and pivotal movement, enabling the rear end 5 of the hood to amply clear the adjacent cowl structure 14 and 1S. Since each of the torsion rods 20 and 23 is prestressed torsionally they act, as described above, to assist opening movement of the hood. The degree or extent of such assist is greatest when the hood is closed, and decreases gradually during hood. opening. This fact, combined with rearward displacement of the center of gravity of the hood, results in the initial overbalanced condition 0f the hood changing gradually to an underbalanced condition thereof, during opening. The p oint o r degree of hood opening at which the hood reaches a point of equilibrium betweenoverbalance and underbalance is designated as the takeover point. The degree of hood opening at which this takeover point occurs will of course, depend upon the degree of prestress of the torsion rods in relation to the weight of the` hood and the relative lengths of the main links and locations of their pivotalconnections 19. In the instant example disclosed, wherein a hood weighing 64 pounds was used, the takeover point occurs at roughly 10 from the zero or hood closed position.

While itis appreciated that torsion bars have been used heretofore for counterbalancing hinges and that the fourlink hinge described above is not itself new, I believe I am the lirst to have so arranged such torsion bars `for operation through idler links connected with the main links of the hinge, and with the torque reaction taken live, i.e. by 4the movable hinged member and the forward link simul- .-taneously, thus employing all the stored energy in the torsion bars to react on the working members of the hinge. By this arrangement, the maximum torsional stress imposed on the rods is held to a value Iwell below commonly accepted design limits, with the result that normal working life is greatly extended. Also by this arrangement of the rods, rtheir bodily movement with the hood provides maximum accessibility under the hood when it is in its open position.l The adapta-bilityof the torsion rods for counterbalancing the hood in the :four-link type hinge arrangement shown also eliminates the added expense of articulating the forward links and the attendant costs of hinge synchronizing means such as are required in -fivelink hinge systems in common usage.v Also, a sturdier construction is obtained, with less freedom of the hood to sway laterally during opening and at full open position.

Whileonly a single preferred embodiment of the invention has been disclosed, it is appreciated that numerous minor changes in the constructionand arrangement of the parts may be made without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

l. yIn combination with a lid movable between open and closed positions by combined pivotal and bodily movement of one edge thereof to effect raising and lowering of its `oppositely disposed edge, a counterbalanced hinge for said lid comprising a movable bracket xed to the lid, a bracket adapted to be fixed to a wall having an opening therein, said lid being I adapted to open and close said opening, two links each pivotally connected at its opposite endsto said respective brackets for movement in the plane of opening and closing movements of the lid, a torsionally elastic member extending normal to said plane and operatively iixed 'at one end to said lid, said member having a crank portion at its opposite end, and a third link connected at one end to said crank portion and pivotally connected at its opposite end to one of said other links intermediate the ends thereof, said member being under torsional 4stress when the hinge is in its lid-closed position such that said crank portion imposes a force couple on the pivotal connections of said one link t o said movable bracket and said third link respectively, in the direction tending to -actuate the hinge toits lid-open position.

2. The invention of claim 1, together with means on said movable bracket journaling said opposite end for rotation and wherein said third link is pivotally connected at its said one end to said crank portion.'

3. The combination with a lid adapted to open and close an opening in a wall, said lid being movable between open and closed positions by combined pivotal 'and bodily movement of one edge thereof to effect raising and lowering of its oppositely disposed edge, of a tour-link hinge therefor in which movement in one plane of a iirst link relative to a second link is controlled by two links having pivotal connections with the iirst and second links, and wherein the relative locations of said pivotal connections effect raising of one end -of said rst link rel-ative to its opposite end during relative movement of said iirst and second links in one direction, said iirst link being iixed to said lid adjacent said one edge thereof, anda torsionally elastic member extending substantially normal to the plane of said movement and having a crank portion, torsion reaction means for said member operatively connected to said lid, and -a iifth link connected at one end to said crank portion and pivotally connected at its opposite end t to one of said two links at a point thereon spaced from both the pivotal connections of said -lirst and second links to said one link, said member being under torsional stress such that said crank portion imposes -a force couple on the pivotal connections of said one link to said first and -fth links, respectively, tending to bias relative movement of said lirst and second links.

4. In combination, a lid anda hinge and connterbalance therefor comprising two swingable links spaced from each other in the plane of opening and closing movements of the lid, a bracket adapted to be fixed to a wall having an opening therein, said lid being adapted to open and close said opening, said bracket having pivotal connections with one end of each -of said links, a second bracket iixed to said lid for movement therewith and having pivotal connections with the opposite end of each of said links, a third link substantially coplanar with said two links and having a pivotal connection with one of said two links at a distance from its pivotal connection lwith said second bracket, and a torsionally elastic member extending substantially normal to said plane and having one of its ends operatively tixed to the lid, said torsionally elastic member having a crank portion Iat its opposite end journaled by said second bracket and operable on the opposite end of said third link to apply a force couple at the pivotal connections of said one link to said second -bracket and third link, respectively, in the lid-opening direction.

5. In a binging and counterbalancing system for a lid to open and close an opening Iin a wall, a Wall defining said opening, a lid for said opening, a pair of hinges, one adjacent each side of the opening, each said hinge comprising two links, each said link having its opposite ends operatively connected to the lid 4and wall for pivotal movement about axes parallel to the plane of said opening, two idler links, one of said idler links having a connection at one end with one of said two links of one of said hinges Ifor pivotal movement about an axis parallel to and at a distance from the axis of pivotal movement between said one link and the lid, the other of said idler links having a like connection with the corresponding one of said two links of the other hinge yand extending therefrom in the same direction as said one idler link, and two torsion springs underlying the lid `and extending between said hinges, one lof said springs having a crank portion operatively journaled by the lid adjacent one of the hinges and the other of said ysprings having a crank portion operatively journaled by the lid adjacent the other of said hinges, each said spring having its end remote from its crank portion operatively llixed tothe lid and its crank portion connected to the `opposite end of the idler link of the hinge adjacent thereto, each said crank portion having an elfective length substantially greater than said distance.

References Cited in the tile of this patent UNITED STATES PATENTS 2,091,673 De Orlow Aug. 31, 1937 2,707,799 Butterfield May 10, 1955 2,895,161 Badura July 21, 1959 

1. IN COMBINATION WITH A LID MOVABLE BETWEEN OPEN AND CLOSED POSITIONS BY COMBINED PIVOTAL AND BODILY MOVEMENT OF ONE EDGE THEREOF TO EFFECT RAISING AND LOWERING OF ITS OPPOSITELY DISPOSED EDGE, A COUNTERBALANCED HINGE FOR SAID LID COMPRISING A MOVABLE BRACKET FIXED TO THE LID, A BRACKET ADAPTED TO BE FIXED TO A WALL HAVING AN OPENING THEREIN, SAID LID BEING ADAPTED TO OPEN AND CLOSE SAID OPENING, TWO LINKS EACH PIVOTALLY CONNECTED AT ITS OPPOSITE ENDS TO SAID RESPECTIVE BRACKETS FOR MOVEMENT IN THE PLANE OF OPENING AND CLOSING MOVEMENTS OF THE LID, A TORSIONALLY ELASTIC MEMBER EXTENDING NORMAL TO SAID PLANE AND OPERATIVELY FIXED AT ONE END TO SAID LID, SAID MEMBER HAVING A CRANK PORTION AT ITS OPPOSITE END, AND A THIRD LINK CONNECTED AT ONE END TO SAID CRANK PORTION AND PIVOTALLY CONNECTED AT ITS OPPOSITE END TO ONE OF SAID OTHER LINKS INTERMEDIATE THE ENDS THEREOF, SAID MEMBER BEING UNDER 